From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764074AbdEAQx3 (ORCPT ); Mon, 1 May 2017 12:53:29 -0400 Received: from g9t1613g.houston.hpe.com ([15.241.32.99]:42084 "EHLO g9t1613g.houston.hpe.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751978AbdEAQxZ (ORCPT ); Mon, 1 May 2017 12:53:25 -0400 From: "Kani, Toshimitsu" To: "dan.j.williams@intel.com" , "vishal.l.verma@intel.com" CC: "linux-kernel@vger.kernel.org" , "linux-nvdimm@lists.01.org" , "dave.jiang@intel.com" Subject: Re: [PATCH] libnvdimm: rework region badblocks clearing Thread-Topic: [PATCH] libnvdimm: rework region badblocks clearing Thread-Index: AQHSwa+nta9I7uFKMkmISr7SDbaEM6HfnXuAgAACnoCAAAJeAIAABYqAgAABTYCAAADqgIAABR+AgAABO4CAAADEgA== Date: Mon, 1 May 2017 16:45:37 +0000 Message-ID: <1493657135.30303.22.camel@hpe.com> References: <149355594185.9917.1577772489949690281.stgit@dwillia2-desk3.amr.corp.intel.com> <1493652871.30303.15.camel@hpe.com> <1493655131.30303.17.camel@hpe.com> <1493655607.30303.19.camel@hpe.com> <1493656965.4424.0.camel@intel.com> In-Reply-To: <1493656965.4424.0.camel@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: intel.com; dkim=none (message not signed) header.d=none;intel.com; dmarc=none action=none header.from=hpe.com; x-originating-ip: [15.219.163.8] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;AT5PR84MB0260;7:csftf/c2Vzb1W+Lj6Ec+1ZzGQRQw2T+hEHoQcjm1J40GKEc3hOTSdkREyFLnz1XZ09dW125nbi2kEyZ2Ts0fGNDIPRRHOZSa9FO90Octja8nfE+/70tlxgw17XifAHjgeNdMEEy1Up1QMUwgtR7smDAEipDAVH3jU1O+rxC//28ibN5ifsjVb7WoZrBPmfyLfqATw/nh3FYHAVlvp+oUxOPE734/+slBc7/sddvjb8D241aVQiZVhZpKOS98mxkj7A5M2Vg/NA2NCdEjLezyQc+gCXr0td34C9hJ+uXF8BQv+3GNZV1gZ7J1dcfAqD7PKgVlK956PeaC6r2ogprQ6Q== x-ms-office365-filtering-correlation-id: ffe7b355-fcb0-4614-5b7b-08d490b17ee9 x-ms-office365-filtering-ht: Tenant x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(22001)(2017030254075)(48565401081)(201703131423075)(201703031133081)(201702281549075);SRVR:AT5PR84MB0260; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(227479698468861); x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(6040450)(601004)(2401047)(5005006)(8121501046)(93006095)(93001095)(3002001)(10201501046)(6055026)(6041248)(20161123564025)(201703131423075)(201702281528075)(201703061421075)(201703061406153)(20161123558100)(20161123562025)(20161123560025)(20161123555025)(6072148);SRVR:AT5PR84MB0260;BCL:0;PCL:0;RULEID:;SRVR:AT5PR84MB0260; x-forefront-prvs: 02945962BD x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(6009001)(39860400002)(39850400002)(39450400003)(39400400002)(39410400002)(39840400002)(377424004)(377454003)(24454002)(3846002)(102836003)(53936002)(6116002)(478600001)(3660700001)(54906002)(103116003)(2906002)(3280700002)(6512007)(81166006)(8936002)(8676002)(38730400002)(2950100002)(86362001)(2501003)(2900100001)(305945005)(54356999)(122556002)(6486002)(6436002)(77096006)(25786009)(33646002)(5660300001)(50986999)(93886004)(7736002)(229853002)(4326008)(36756003)(76176999)(189998001)(6506006);DIR:OUT;SFP:1102;SCL:1;SRVR:AT5PR84MB0260;H:AT5PR84MB0260.NAMPRD84.PROD.OUTLOOK.COM;FPR:;SPF:None;MLV:sfv;LANG:en; spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 X-MS-Exchange-CrossTenant-originalarrivaltime: 01 May 2017 16:45:37.6728 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 105b2061-b669-4b31-92ac-24d304d195dc X-MS-Exchange-Transport-CrossTenantHeadersStamped: AT5PR84MB0260 X-OriginatorOrg: hpe.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id v41GrhGS010242 On Mon, 2017-05-01 at 16:42 +0000, Verma, Vishal L wrote: > On Mon, 2017-05-01 at 09:38 -0700, Dan Williams wrote: > > On Mon, May 1, 2017 at 9:20 AM, Kani, Toshimitsu > > : > > > > > > > > Hi Dan, > > > > > > > > > > > > > > > > I was testing the change with CONFIG_DEBUG_ATOMIC_SLEEP > > > > > > > > set this time, and hit the following BUG with > > > > > > > > BTT.  This is a separate issue (not introduced by this > > > > > > > > patch), but it shows that we have an issue with the DSM > > > > > > > > call path as well. > > > > > > > > > > > > > > Ah, great find, thanks! We don't see this in the unit > > > > > > > tests because the nfit_test infrastructure takes no > > > > > > > sleeping actions in its simulated DSM path. Outside of > > > > > > > converting btt to use sleeping locks I'm not sure I see a > > > > > > > path forward. I wonder how bad the performance impact of > > > > > > > that would be? Perhaps with opportunistic spinning it > > > > > > > won't be so bad, but I don't see another choice. > > > > > > > > > > > > It's worse than that. Part of the performance optimization > > > > > > of BTT I/O was to avoid locking altogether when we could > > > > > > rely on a BTT lane percpu, so that would also need to be > > > > > > removed. > > > > > > > > > > I do not have a good idea either, but I'd rather disable this > > > > > clearing in the regular BTT write path than adding sleeping > > > > > locks to BTT. Clearing a bad block in the BTT write path is > > > > > difficult/challenging since it allocates a new block. > > > > > > > > Actually, that may make things easier. Can we teach BTT to > > > > track error blocks and clear them before they are reassigned? > > > > > > I was thinking the same after sending it.  I think we should be > > > able to do that. > > > > Ok, but we obviously can't develop something that detailed while > > the merge window is open, so I think that means we need to revert > > commit e88da7998d7d "Revert 'libnvdimm: band aid btt vs clear > > poison locking'" and leave BTT I/O-error-clearing disabled for this > > cycle and try again for 4.13. > > Agreed, I'll work on something to track badblocks and clear them > outside the IO path. Great! Thanks Vishal! -Toshi